vac. pressure good sometimes???

[sk8rfreak345]

I have a ka24det running weird.

9 out of 10 times I start it, the vacuum gauge reads -17, idles sputtering, running really rich, black smoke. (when i try to accelerate it doesn't hold boost)

that other 1/10 times it will start up perfect, vacuum at -23, perfect idle, no smoke, holds boost almost perfectly (~6psi.).

i have 2 separate maf's that i have tried with no success. checked for leaks and fixed them except a small one by the iacv.

So what could be causing it to work right occasionally? any suggestions?(seems it would be something electrical.) thanks in advance for any helpful comments, and yes i have searched, cant find any cases that completely match mine.

if it helps at all its has a s14 t28, sr injectors, an n60 maf and an Enthalpy tune.

[sk8rfreak345]

no one has a clue?

[bkt808]

my rb was doing this, it was a loose fuel rail causing a vacuum leak at the injector to manifold o-rings. sometimes the vacuum would seal the injectors to the rings and idle good and when id hit boost it would open up the leak and idle bad when it came back down to idle

[sk8rfreak345]

Yea I didn't notice a vacuum leak at the insulators but I'll go ahead and replace them and see what happens. Thanks!